ABSTRACT
Suh and Corbett 1 determined the Hildebrand parameters of three random copolymer samples by the turbidimetric titration of solutions in two solvents with two nonsolvents, using the intercept method of Suh and Clarke. 2 Details appear in Table 1, together with subsequent results based on this work. Boyer and Keskkula 3 reported these values, as well as preferred values selected by Suh, Clarke, and Keskkula. Schneier 4 applied his equation for random copolymer blends, showing that an acrylonitrile Hildebrand parameter of 27.1 MPal/2 gave better agreement with the copolymer experimental values than did the 26.1 MPa1/2 of Small 5 or the 31.5 MPa1/2 of Tobolsky. 6 Hildebrand Parameters of Random Styrene–Acrylonitrile Copolymers, from the Turbidimetry Studies of Suh and Clarke and the Subsequent Reports of Boyer and Keskkula and of Schneier
Styrene/acrylonitrile (j/k) ratio
75.5/24.5
75.5/24.5
71/29
j x
0.858
0.858
0.867
k x
0.142
0.142
0.133
10–3 M w
171
209
207
M w/M n
2.2
2.2
2.2
Density/g cm–3
1.08
1.08
1.08
Solvents
Benzene
Benzene
Chlorobenzene
o-Dichlorobenzene
o-Dichlorobenzene
o-Dichlorobenzene
Nonsolvents
Tetrachloromethane
Tetrachloromethane
Toluene
n-Amyl alcohol
n-Amyl alcohol
n-Amyl alcohol
δ/MPa1/2 (Suh and Corbett)
19.6
19.6
20.0
δ/MPa1/2
19.2—19.7
19.0—20.2
19.7—20.3
(Boyer and Keskkula)
δ/MPa1/2 (preferred)
19.6
19.6
20.1
δ/MPa1/2 (Schneier)
(With j δ = 27.1 MPal/2)
19.6
19.6
20.0
(With j δ = 26.1 MPa1/2)
19.0
19.0
19.4
(With j δ = 31.5 MPa1/2)
19.7
19.7
20.1
